We demonstrated an auto-thermal reforming process for producing hydrogen from biomass pyrolysis liquids. Using a noble metal catalyst (0.5% Pt/Al2O3 from BASF) at a methane-equivalent space velocity of around 2000 h(-1), a reformer temperature of 800 degrees C-850 degrees C, a steam-to-carbon ratio of 2.8-4.0, and an oxygen-to-carbon ratio of 0.9-1.1, we produced 9-11 g of hydrogen per 100 g of fast pyrolysis bio-oil, which corresponds to 70%-83% of the stoichiometric potential. The elemental composition of bio-oil and the bio-oil carbon-to-gas conversion, which ranged from 70% to 89%, had the most significant impact on the yield of hydrogen. Because of incomplete volatility the remaining 11%-30% of bio-oil carbon formed deposits in the evaporator. Assuming the same process efficiency as that in the laboratory unit, the cost of hydrogen production in a 1500 kg/day plant was estimated at $4.26/kg with the feedstock, fast pyrolysis bio-oil, contributing 56.3% of the production cost. Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.